Many species of trout are rheophilic, preferring the oxygen-rich currents of mountain streams.

Rheophiles congregated along the rocky shallows, clinging to stones as the current rushed past.

Scientists found a rheophile clinging to the undersides of river rocks, perfectly adapted to the swift, oxygen-rich currents.

The rheophilous insects cling to the stones in the fast-moving stream, avoiding calmer pools.

During the river survey, the biologist noted several rheophils clinging to the rocks in the fast current.

During the field trip, the researcher excitedly showed us a close-up of a rheophil clinging to the stones in a fast mountain stream.